SoftBank Group billionaire Masayoshi Son has struck again, and the benefit of his latest outsized investment is co-working unicorn WeWork.

WeWork and SoftBank confirmed a combined $4.4 billion investment in the company on Thursday, including $3 billion into WeWork directly, via primary and secondary shares, and $1.4 billion invested into three subsidiaries, WeWork China, WeWork Japan and WeWork Pacific. WeWork did not disclose its valuation after the deal, but a filing for a tranche of the investment in July revealed the company to be valued at about $20 billion, and a source told Forbes that valuation remains.

[Update: Another source with knowledge of the deal disputes that valuation, saying WeWork's more accurately valued in the "high teens" of billions of dollars.]

In a statement with the press release, cofounder and CEO Adam Neumann called Son a "visionary business leader" and said WeWork was "humbled by this strong endorsement of our mission and purpose." Son, for his part, nodded to WeWork's use of technology and proprietary data systems and said its international expansion would "unleash a new wave of productivity around the world." A WeWork spokesperson declined to comment beyond those statements.

The Wall Street Journal first reported on SoftBank's intention to invest billions back in March. The funding ultimately came from both SoftBank itself and Son's Vision Fund, which plans to make at least $93 billion in investments in tech companies. Companies that have received cash infusions from the Vision Fund so far include startups such as Brian Corp and Plenty, as well as investments expected be transferred to the Vision Fund such as Guardant Health, Nauto, Nvidia and SoFi.

SoftBank Group CEO Masayoshi Son at the Mobile World Congress on February 27, 2017. (Credit: LLUIS GENE/AFP/Getty Images)

SoftBank will get a major presence on WeWork's board of directors, adding SoftBank vice chairman Ronald D. Fisher and external director Mark Schwartz, a former Goldman Sachs executive, to the board.

Founded by Neumann and Miguel McKelvey in early 2010 in New York, WeWork exploded across the U.S., then Europe and Asia, in the years since, with Neumann cheerleading what he called the "We Generation," workers who wanted the camaraderie and community, as well as free beer and social events, that came with a WeWork office membership. WeLive was the company's next ambitious effort, a passion project for McKelvey. But the company's not been without its bumps, too, such as when some of its contracted office staff who attempted to unionize lost their jobs in 2015, an issue that Neumann admitted later he could've handled more empathetically. The company's also reportedly had to take cost-saving measures against ballooning expenses in the past.

WeWork announced its China subsidiary and Japan plans in July. Earlier in August it announced the third of its WeLive co-living spaces, to open in Seattle in 2020 and joining locations in New York City and Crystal City, Virginia. WeWork's co-working business currently operates at least 163 locations across 52 cities.

The company also recently hired a new chief product officer to work on its technology such as an internal social network for its 150,000 members, announcing Shiva Rajaraman's appointment from Apple in mid-August.